Research to find out about the characteristics and behavior of people has been conducted based on the characteristics and behavior of animals excluding humans. In particular, it has been established that the visual phenomena which are referred to as subjective contours, a modal completion, and transparency in human visual psychology are processed in the brain in animals other than humans (called simply ‘animals’ hereinbelow).
Therefore, research into visual phenomena is performed by making the experiment subject an animal and, in particular, a small primate such as a squirrel monkey (Non-Patent Document 1 (‘Animal psychology research’, Japanese Animal Psychology Society, 50th Edition, Volume 1, pages 61 to 73, (2000) and Non-Patent Document 2 (St. Paul's University Psychology Research’, published by St. Paul's University Department of Psychology Studies, 2001, Vol. 43, pages 19 to 23)).
In cases where psychological experiments are performed on such an animal, the animal serving as the experiment subject must be in a relaxed state without being agitated so as to be able to respond to the experiment problem in order to obtain more reliable experiment data.
Conventionally, examples of systems for performing these kinds of psychological experiments of visual phenomena using animals include systems, that is, response acquisition devices that use an infrared touch panel (Non-Patent Document 3 (‘St. Paul's University Psychological Research’, published by St. Paul's University Department of Psychological Studies, 46th Edition (2004), excerpts, pages 33 to 41)).
With such conventional systems, an experiment subject such as a squirrel monkey, for example, which is contained in a cage known as an ‘operand box’, undergoes an experiment completely unrestrained in the cage. Alternatively, the experiment subject undergoes the experiment in a state where the upper half of the squirrel monkey is unrestrained, and in a state where the lower half thereof is restrained from moving freely.
However, a ‘primate retention device’, that is, a ‘restraint device’, which is employed in order to perform an experiment for the administration of drugs given to humans or other desired experiments on an animal such as a squirrel monkey, has been proposed. This restraint device restrains the monkey by pushing the monkey so that same is unable to move freely in the space between a lattice-like movable barrier wall and a lattice-like rear wall which is capable of opening and closing. In order to more reliably restrain the behavior of the squirrel monkey, the restraint device has a structure that involves attaching a ring to the monkey's collar, inserting a rod in the ring, and fixing the other end of the rod to the lattice of either wall (Patent Document 1).
Patent Document 1: Japanese Publication No. H8-24506
Non-Patent Document 1: ‘Animal psychology research’, Japanese Animal Psychology Society, 50th Edition, Volume 1, pages 61 to 73, (2000)
Non-Patent Document 2: St. Paul's University Psychology Research’, published by St. Paul's University Department of Psychology Studies, 2001, Vol. 43, pages 19 to 23
Non-Patent Document 3: ‘St. Paul's University Psychological Research’, published by St. Paul's University Department of Psychological Studies, 46th Edition (2004), excerpts, pages 33 to 41.